has long spied to friendly foreign leaders to understanding the thinking of both enemies and allies. >> it's invaluable to us to know where countries are coming from, what their policies are, how that would impact us across a whole range of issues. >> reporter: german chancellor angela merkel has accused the u.s. of monitoring her personal cell phone. senate intelligence committee member, republican susan collins, said today that's inappropriate. >> there's absolutely no justification for our country to be collecting intelligence information on the leaders of some of our closest allies. >> reporter: but before the house intelligence committee, clapper was unapologetic. >> some of this reminds me a lot of classic movie ""casablanca--" my god, there's gambling going on here poopts the same kind of thing. >> reporter: national security agency chief keith alexander said european partners have not been shy about spying on the u.s. alexander was questioned by minnesota republican michele bachmann. >> is it your experience that allies of the united states have spied on the united states his